Maha Ashtami, also known as Ashtami and Durgashtami, It is one of the most important days during the auspicious festivals of Navratri and Durga Puja. They are dedicated to Maa Durga and her nine avatars (Navdurgas). Devotees worship the Goddess and her nine forms, honouring the victory of good over evil. During Ashtami, people worship Maa Mahagauri and perform various rituals, including Kanjak or Kanya Puja etc.
Navratri Day 8 Significance:

The eighth day of Navratri or the third day of Durga Puja, Maha Ashtami, celebrates Maa Durga’s victory over the buffalo demon Mahishasura. People worship Maa Mahagauri on this day, who is known for bestowing her devotees with wealth and an opulent lifestyle, and removing all their sufferings. Praying to Maa Durga during Ashtami can help rid one of all their problems and sins. Ashtami fast also holds significance as it brings prosperity and luck.In some parts of India, people also perform Astra Puja during Ashtami. Many devotees consider it an auspicious day to pray to their tools. Additionally, Maa Durga’s weapons are worshipped as symbols of female strength.
Navratri Day 8 Puja Vidhi and Samagri:

On Ashtami, devotees should begin the day with Mahasnan to rid themselves of impurities and wear new clothes. Then, install nine small pots to invoke nine Shaktis of Maa Durga and worship them during Maha Ashtami Puja. People also welcome nine young unmarried girls into their houses to perform Kanjak or Kanya/Kumari Puja, as they are considered divine manifestations of Maa Durga. These girls sit in one line, and devotees tie a holy dhaaga on their wrists. Then, the devotees wash their feet, put tilak on their foreheads, and offer the girls specially-prepared prasad comprising of puri, halva and black grams. Lastly, people also perform Sandhi Puja on this day.
Navratri Day 8 Bhog:
On the eighth day, worshippers offer a special bhog of coconut to Goddess Mahagauri. It is widely believed that donating coconuts to the Brahmins on Ashtami brings prosperity and happiness.
Navratri Day 8 Colour:
The colour of the day on Maha Ashtami or Day 8 of Navratri is peacock green. Devotees who worship Goddess Mahagauri on this day can wear clothes of this shade. The colour is a symbol of uniqueness, individuality, compassion, and freshness.
Navratri Day 8 Mantra and Prarthana:

1) Om Devi Mahagauryai Namah